Microfluidic Production of Microbubbles

Microbubbles are the most widely used ultrasound contrast agent and can be fabricated in a number of ways, including via sonication, agitation, and microfluidics.


Hossack lab studies the use of the microbubbles as imaging contrast agents and as therapeutic agents for drug delivery and sonothrombolysis. As shown below, microfluidic production occurs at the expanding nozzle of a microfluidic device, where precisely controlled gas and liquid streams meet to form microbubbles through a variety of pinch-off mechanisms. This method of microbubble production is capable of fabricating microbubbles of uniform size distribution at rates as high as 1 million microbubbles per second. We are also investigating the use of this technology in catheter-based applications and are in the process of developing on-chip electrical control and monitoring systems to regulate device operation in real-time.

 

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Dixon, Ultrasound in Medicine and Biology, 2013

 

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Dhanaliwala, Biomedical Microdevices, 2015

 

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Dixon, Annals of BME, submitted 2017

 

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Rickel, IUS 2017

Our Research Areas

  • Ultrasound Molecular Imaging

    Ultrasound molecular imaging is a powerful imaging method which utilizes microbubble contrast agents to target and bind disease markers in the blood vessels. While traditional imaging methods detect disease by gross anatomical features, we aim to detect disease on a molecular level. This unprecedented level of imaging sensitivity can not only improve the contrast and clarity of diagnostic images, but significantly improve patient outcomes as physicians make faster, more accurate diagnoses. In our lab, we program ultrasound imaging sequences and image processing techniques to improve the contrast and isolation of microbubble signals. Our studies work to advance the field of ultrasound molecular imaging toward rapid clinical adoption.

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  • Microfluidic Production of Microbubbles

    Microbubbles are the most widely used ultrasound contrast agent and can be fabricated in a number of ways, including via sonication, agitation, and microfluidics. Hossack lab studies the use of the microbubbles as imaging contrast agents and as therapeutic agents for drug delivery and sonothrombolysis. We are also investigating the use of this technology in catheter-based applications and are in the process of developing on-chip electrical control and monitoring systems to regulate device operation in real-time.

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  • Photoacoustic Imaging

    Our lab develops and investigates the properties of photoacoustic contrast agents based on microbubble and perfluorocarbon droplet platforms. These contrast agents integrate light absorbing nanoparticles, like gold nanorods (AuNR), on their surface and absorb light energy. The resulting photoacoustic responses are significantly larger and carry unique information, which allows them to be differentiated from photoacoustic signals originating from the surrounding tissue. Potential applications of these agents include molecular imaging, tracking of drug-loaded particles, and monitoring the release of drugs from activatable drug carriers.

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  • Ultrasound Artifact Reduction

    Echocardiography is frequently used to assess cardiac function. However, getting a diagnostic quality echocardiographic image is often difficult due reflections from the surrounding anatomy and subcutaneous fat. These reflections are super imposed on the moving heart and hinder diagnosis. In the Hossack Lab we develop signal processing methods to eliminate artifacts while retaining the underlying tissue. We confirm that the underlying tissue is retained by wall motion tracking analysis.  

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